Nylon gnaw sticks for rats: an effect that goes beyond the teeth
A nylon gnaw stick looks like a harmless accessory, reduced to its role in wearing down teeth. A recent study shows its effect reaches further, down to the gut microbiome and certain immune markers. Find our enrichment ideas in the toys and enrichment section.
A study that goes beyond dental health
Wulczynski, Brooks, Green, Matias, Kalmokoff, Green-Johnson and Clarke published a study in the journal Animal Microbiome in 2025 on the effect of nylon gnaw sticks offered as enrichment to Sprague Dawley rats (research on Google Scholar). The authors found measurable variation in immune parameters and lower gastrointestinal fermentation among animals with access to these sticks, with marked differences depending on whether the individual was male or female.
A toy that acts beyond the jaw
This finding is a reminder that a chew accessory isn't neutral for the body as a whole: beyond its well-known role in wearing down continuously growing teeth, the material ingested in small amounts during gnawing interacts with gut flora and certain immune markers, an effect that had been little documented for this common type of accessory.
Should nylon gnaw sticks be avoided altogether?
No: the study found no sign of toxicity or clear digestive trouble, only a measurable physiological variation under lab conditions. It instead suggests not relying exclusively and permanently on a single gnawing material.
- Rotate materials: untreated wood, cardboard, natural-fiber rope and nylon rather than a single type of stick used continuously.
- Watch the animal's stool when introducing a new gnawing material, as you would with any dietary change.
- Choose accessories made for rodents rather than household plastic objects never intended to be chewed.
This diversification builds on the benchmarks already covered in our article on chew toys and rodent dental health. For a complete setup suited to rats, our guide on pet rat enrichment covers the other activities to combine with gnawing.
Frequently asked questions
Should all nylon toys be removed from the cage?
No, nothing indicates they're dangerous; what matters is not relying on them exclusively and offering several materials in rotation.
Does this study also apply to mice or guinea pigs?
The protocol was run specifically on Sprague Dawley rats; nothing confirms the effect is identical in other rodent species.
Do the differences between males and females change practical recommendations?
Not directly for an owner: the observed variation remains a physiological parameter measured in the lab, with no known translation into a clinical sign to watch for day to day. Find all our guides on the rodent hub.
This guide is part of Planète Pets’s Rodents universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.